Class: Philiprehberger::Tar::Reader

Inherits:
Object
  • Object
show all
Defined in:
lib/philiprehberger/tar/reader.rb

Overview

Reads and extracts tar archives.

Constant Summary collapse

BLOCK_SIZE = 
512

Instance Method Summary collapse

Constructor Details

#initialize(io) ⇒ Reader

Returns a new instance of Reader.

Parameters:

  • io (IO) —

    the input stream



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# File 'lib/philiprehberger/tar/reader.rb', line 10

def initialize(io)
  @io = io
end

Instance Method Details

#each_entry {|Hash| ... } ⇒ Array<Hash>

Iterate over each entry in the archive.

Yields:

  • (Hash) —

    entry info with :name, :size, :mode, :typeflag, :linkname, :content keys

Returns:

  • (Array<Hash>) —

    entries if no block given



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# File 'lib/philiprehberger/tar/reader.rb', line 18

def each_entry(&block)
  entries = []

  loop do
    header = @io.read(BLOCK_SIZE)
    break if header.nil? || header.bytesize < BLOCK_SIZE
    break if header == "\0" * BLOCK_SIZE

    entry = parse_header(header)
    break if entry[:name].empty?

    if entry[:typeflag] == '2'
      # Symlink entry has no content
      entry[:content] = ''
    else
      content = read_content(entry[:size])
      entry[:content] = content
    end

    if block
      block.call(entry)
    else
      entries << entry
    end
  end

  entries unless block
end

#entry?(name) ⇒ Boolean

Check whether the archive contains an entry with the given name, without reading entry content.

Parameters:

  • name (String) —

    the entry name to search for

Returns:

  • (Boolean) —

    true if the entry exists in the archive



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# File 'lib/philiprehberger/tar/reader.rb', line 52

def entry?(name)
  loop do
    header = @io.read(BLOCK_SIZE)
    break if header.nil? || header.bytesize < BLOCK_SIZE
    break if header == "\0" * BLOCK_SIZE

    entry = parse_header(header)
    break if entry[:name].empty?

    return true if entry[:name] == name

    skip_content(entry[:size]) unless entry[:typeflag] == '2'
  end

  false
end

#list ⇒ Array<Hash>

List all entries without reading content.

Returns:

  • (Array<Hash>) —

    entry info hashes with :name, :size, :mode, :typeflag, :linkname keys



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# File 'lib/philiprehberger/tar/reader.rb', line 72

def list
  result = []

  loop do
    header = @io.read(BLOCK_SIZE)
    break if header.nil? || header.bytesize < BLOCK_SIZE
    break if header == "\0" * BLOCK_SIZE

    entry = parse_header(header)
    break if entry[:name].empty?

    result << { name: entry[:name], size: entry[:size], mode: entry[:mode],
                typeflag: entry[:typeflag], linkname: entry[:linkname] }
    skip_content(entry[:size]) unless entry[:typeflag] == '2'
  end

  result
end